Cumulative effects assessment: proof of concept marine mammals

Abstract

This development of the framework and approach for a Cumulative Effects Assessment (CEA) is based on a literature review. The literature identified some key challenges that need to be addressed for CEA to evolve into a consistent, appropriate tool to assist decision-making. These challenges included • A clear distinction of the receptor-led CEA from the dominating stressor-led Environmental Impact Assessment (EIA) approaches and • Enabling CEA to provide ecosystem-relevant information at an appropriate regional scale. Therefore this CEA is explicitly developed to be a receptor-led and fully integrated framework, i.e. involving multiple occurrences of multiple pressures (from single and/or different sources) on multiple receptors, as opposed to other existing approaches dealing with only a subset of those pressures or receptors, hence our use of the phrase iCEA for integrated CEA. As a proof of concept for this iCEA we selected one receptor, the ecosystem component marine mammals. The main conclusions of this exercise (see Chapter 6) are that the iCEA framework and approach presented in this study appear suitable to fulfil its main purpose and ultimately inform the policy process as described in the conception phase. However it should be acknowledged this is only the very first step in a process where through many iterations new information can be introduced and assessed (relative to existing information) based on the criteria provided resulting in an improved iCEA with increasing confidence levels. As more information becomes available the relative importance of impact chains and its corresponding information modules may change giving direction to new areas for research. For further development of this iCEA towards its intended applications we can distinguish between the first purpose, i.e. identification of the main impact chains contributing to the risk that a specific ecosystem component is impacted, which can be achieved with the approach presented here focussing on one specific ecosystem component and the second purpose, i.e. an evaluation of the performance of possible management strategies, which would require all ecosystem components to be included as would be required for ecosystem-based management. Thus to further the development and application of this iCEA towards its (two) purpose(s) the recommendation is to: • Include the available information presented in this report into the iCEA and develop the Bayesian Belief Network such that it can process this information and its associated confidence into an assessment that identifies the main impact chains for the marine mammals. • Extend the framework and approach to (all) the other ecosystem components so that a truly integrated CEA is possible. Note that this is likely to affect the identification of what should be considered the main pressures to guide management. • Improve the information modules that emerged from the evaluation as the most promising to increase the confidence in the outcome of the iCEA. Note that the previous two steps may result in a different prioritisation of the information modules as the importance of pressures and hence impact chains changes.